Category Archives: bushfires

Bushfires and Wild Fires

Significant heatwave – South West United States – July 2021

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An intense heatwave has gripped the South West United States for much of the start of July 2021 which has seen near record temperatures occur at certain locations and in one case, a possible new temperature record for the United States being the highest “minimum overnight temperature” recorded.

A weather station at Stovepipe Wells in Death Valley appears to have recorded a minimum overnight temperature of 42.1C which was recorded at 5.25 am on July 12 2021. The temperature recordings for this weather station appear to be:-

2 am - 46.1C or 115F.

4 am - 44.9C or 113F.

5.25 am - 42.1C or 108F.

6 am - 43.6C or 110.5F.

If confirmed, this would break the record currently held at nearby Furnace Creek being 41.7C or 107F recorded on July 12 2012.

I travelled to this location in June 2007 and as shown in the attached photo of nearby Badwater Basin just to the south of Furnace Creek, it is easy to see why such high daily temperature extremes occur here year after year.

Minimum overnight temperatures of 40C are rare anywhere in the world but Death Valley is one of a very few places globally where this can occur due to the topography of the region. The mountain ranges to the east and west play a significant role in trapping in the heat of the day allowing little to escape overnight.

In addition, this heatwave has seen a maximum temperature reach 54.4C or 130F at Furnace Creek on July 9 2021 at 5.00 pm. At Furnace Creek, it reached 53.5C on the 10/7/2021 and 53C on the 11/7/2021 which is significant even for this desert location. A temperature of 54.4C could be amongst the highest verified temperature ever recorded anywhere however this is now subject to intense review.

The official recording for this station is attached to the post for July 9 2021 with the 5 pm temperature of 130F (54.4C) highlighted in blue for clarity.

The heatwave has impacted much of the south west United States including inland California, Arizona, Nevada and even into a portion of Utah where the city of St George recorded 46C on the 10 July 2021. What makes this temperature more impressive is that the weather station lies approximately 860 metres above sea level (Almost the same elevation as Orange in New South Wales for comparison).

Lake Havasu City topped 48C or 118F on July 9. Even more remarkable was that at 1.15 am on July 10, it was still 40C (104F) with the overnight minimum dropping to around 36.5C or 97F at 5.15 am and back up to 100F or 37.8C at 7.15 am. This area is also susceptible to intense summer heatwaves due to location and proximity of nearby mountain ranges trapping in the summer heat.

The worst affected cities are Palm Springs, Yuma, Lake Havasu City and Las Vegas. The heat has contributed to fires in California, significant stress to dwindling water supplies and current drought conditions worsening.

Significant hot weather has also occurred across the inland areas of Oregon and Washington States east of the Cascades and across low lying areas of Idaho where several fires burn. There is significant fire activity south east of Crater Lake in Oregon and another significant blaze north of Fresno in California.

The attached satellite photo taken from NASA’s worldview dated Monday 12 July 2021 is showing one of the largest fires so far this season near Klamath Falls in southern Oregon with a thick smoke plume extending hundreds of kilometers towards the north east and impacting the air quality over Boise (Idaho).

The heatwave is starting to ease across the south west as monsoonal moisture increases bringing with it isolated thunderstorms and the potential for local flash flood episodes.

The current heatwave may have set a few temperature records although such records now need to be proven and reviewed prior to the recordings being confirmed within official data.

Rain and storms December 29 and 30 2020 while dry in SW New South Wales.

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Similar to the previous post, rain continues to drench parts of eastern New South Wales while the south and west of the state remains dry resulting in wide variations of weather.

For the 24 hour period to 9 am 30/12/2020, Mona Vale in north east Sydney was drenched with 105 mm with falls of 73 to 78 mm falling in nearby suburbs.

Constant rain has also featured across other parts of New South Wales and cumulative totals are mounting.

For the period 1 December to the 30 December 2020, Horsley Park in Sydney's west has received 112 mm of rain against an average of 69.9 mm while Penrith has received 117 mm against an average of 65 mm. Furthermore, Sydney City has received 118 mm against an average of 77.1 mm.

Afternoon thunderstorms featured across Sydney and areas further north on the Monday 28 December 2020 although we were in Albury.

Interestingly, following the passage of the cold front in southern New South Wales , large banks of alto cumulus castellatus clouds dominated the sky for much of the morning although this cleared during the afternoon.

During the drive from Albury to Sydney on the 29/12/2020, we left Albury under clear skies. At Wagga Wagga, it was clear and sunny. At Gundagai, small cumulus clouds were observed. Between Gundagai and Yass, more and more clouds were observed and by the time we reached Goulburn, it was cool and cloudy with occasional drizzle patches. We reached Sydney under showery skies.

There has been a distinct dry line between the wetter eastern half and the drier western half centred close to Conroys Gap. Conroys Gap is a pass that rises approximately 650 metres in height being part of a wider north to south range of hills that divides the southern tablelands with the slopes and plains just to the west of Yass. This is where the boundary between the two air masses has been situated over the past few days.

In this instance, the eastern half has seen much of the rain while the south and west has missed the event.

Weather models are now showing and suggesting that some of the rain and storms should start to penetrate further inland thus reaching some of the drier western and southern areas during the period 31 December 2020 to the 6 January 2021. Rainfall models do suggest falls of 25 mm to 50 mm for the drier regions with continued rain for the eastern half of the state.

The attached photo taken just east of Albury (27/12/2020 looking west) is showing the typical weather conditions being experienced in southern New South Wales ahead of the most recent cool change being thin high cloud as temperatures soared close to 36C. However with elevated fire danger, fires have been a concern. The plume of smoke from a grass or bushfire is visible on the distant hills. With forecast rain over coming days, the elevated fire danger should be reduced.

The attached model from the Bureau of Meteorology "Water and the Land" site prepared on the 30/12/2020 is showing forecast rainfall up to the 6/1/2021. It is showing that most of New South Wales including the drier areas should benefit from the developing weather system.

Images January 2020 Bushfires west of Sydney

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The photos attached to this post are taken just south of Penrith NSW and around Warragamba Dam.

During December 2019 and January 2020 vast areas of the Blue Mountains west of Sydney and areas around Silverdale and Warragamba Dam were scorched by bushfires and between October 2019 and February 2020 plumes of smoke covered large areas of Sydney for days at a time.

The images attached to this post were taken during January 2020 showing one of the out of control bushfires burning close to the township of Warragamba and the evening sunset image was taken just south of Penrith NSW.

According to Australian Geographic (March / April 2020 edition, Page 45) the fires across eastern Australia burnt approximately 16 million hectares, with 5,900 buildings destroyed, some 250,000 people required to evacuate (including my parents and my wife and I at Batemans Bay on December 31 2019), some 140 aircraft used during the crises, over 3,000 homes lost, large numbers of animals killed (Exact toll will never be known) and 33 fatalities. The full economic losses are still being worked out.

West of Sydney, more than 80% of the World Heritage listed Greater Blue Mountains area was impacted. The bushfire crises came to an end during the early part of February 2020 as a result of a major rain event and a reversal of the weather systems in play.

At the time the images were taken in January 2020, my my wife and I were watching this fire burn from a safe distance and occasionally watching aircraft make low level water bombing.

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